python DataFrame数据合并 merge()、concat()方法，2024年最新进阶加薪全靠它_dataframe merge

df_merge = pd.merge(df1, df2, on=‘id’, how=‘left’)

print(df_merge)

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right

使用来自右数据集的键

df_merge = pd.merge(df1, df2, on=‘id’, how=‘right’)

print(df_merge)

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2.多对一合并

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import pandas as pd

df1 = pd.DataFrame({‘id’: [‘001’, ‘002’, ‘003’],

‘num1’: [120, 101, 104],

‘num2’: [110, 102, 121],

‘num3’: [105, 120, 113]})

df2 = pd.DataFrame({‘id’: [‘001’, ‘001’, ‘003’],

‘num4’: [80, 86, 79]})

print(df1)

print(“=======================================”)

print(df2)

print(“=======================================”)

如图，df2中有重复id1的数据。

合并

df_merge = pd.merge(df1, df2, on=‘id’)

print(df_merge)

合并结果如图所示：